package com.hq.lib_comview.common.utils;

import android.util.Base64;

import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;


/**
 * DES加密和解密工具,可以对字符串进行加密和解密操作  。
 *
 * @author Pxie
 */

public class DesUtils {

    private final static String DES = "DES";

    private final static String key = "Yryz@Adm1n!";


    /**
     * Description 根据键值进行加密
     *
     * @param data
     * @return
     * @throws Exception
     */
    public static String encrypt(String data) {
        try {
            byte[] bt = encrypt(data.getBytes(), key.getBytes());
            String strs = Base64.encodeToString(bt, Base64.DEFAULT);
            return strs;
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }
    }

//    /**
//     * Description 根据键值进行解密
//     * @param data
//     * @param key  加密键byte数组
//     * @return
//     * @throws IOException
//     * @throws Exception
//     */
//    public static String decrypt(String data) throws IOException,
//            Exception {
//        if (data == null)
//            return null;
//        BASE64Decoder decoder = new BASE64Decoder();
//        byte[] buf = decoder.decodeBuffer(data);
//        byte[] bt = decrypt(buf,key.getBytes());
//        return new String(bt);
//    }

    /**
     * Description 根据键值进行加密
     *
     * @param data
     * @param key  加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成加密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }


    /**
     * Description 根据键值进行解密
     *
     * @param data
     * @param key  加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成解密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }
}
